seventeen

From Longman Dictionary of Contemporary Englishseventeensev‧en‧teen /ˌsevənˈtiːn◂/ ●●●S3W3 numberthe number 17a group of seventeen American military officersI left home when I was seventeen (=17 years old). —seventeenth adjective, pronounin the seventeenth centuryher seventeenth birthdayI’m planning to leave on the seventeenth (=the 17th day of the month).